var localData = {
        hname:location.hostname?location.hostname:'localStatus',
        isLocalStorage:window.localStorage?true:false,
        dataDom:null,

        initDom:function(){ //初始化userData
            if(!this.dataDom){
                try{
                    this.dataDom = document.createElement('input');//这里使用hidden的input元素
                    this.dataDom.type = 'hidden';
                    this.dataDom.style.display = "none";
                    //this.dataDom.addBehavior('#default#userData');//这是userData的语法
                    document.body.appendChild(this.dataDom);
                    var exDate = new Date();
                    exDate = exDate.getDate()+30;
                    this.dataDom.expires = exDate.toUTCString();//设定过期时间
                }catch(ex){
                    return false;
                }
            }
            return true;
        },
        set:function(key,value){
            if(this.isLocalStorage){
                window.localStorage.setItem(key,value);
            }else{
                if(this.initDom()){
                    this.dataDom.load(this.hname);
                    this.dataDom.setAttribute(key,value);
                    this.dataDom.save(this.hname);
                }
            }
        },
        get:function(key){
            if(this.isLocalStorage){
                return window.localStorage.getItem(key);
            }else{
                if(this.initDom()){
                    this.dataDom.load(this.hname);
                    return this.dataDom.getAttribute(key);
                }
            }
        },
        remove:function(key){
            if(this.isLocalStorage){
                localStorage.removeItem(key);
            }else{
                if(this.initDom()){
                    this.dataDom.load(this.hname);
                    this.dataDom.removeAttribute(key);
                    this.dataDom.save(this.hname);
                }
            }
        },
        clear:function(){
            if(this.initDom()){
                localStorage.clear();
            }
        }
    };
    
    /*
    localStorage.getItem(key):获取指定key本地存储的值
    localStorage.setItem(key,value)：将value存储到key字段
    localStorage.removeItem(key):删除指定key本地存储的值
    localStorage.clear():清空所有本地存储
    */
    localData.initDom(); //初始化
   // alert(window.localStorage);